Edwin t



(N0 Model.)

' E. .T. GREENPIELD 85 J, NAGEL.

TUBE.

No 442,090. Patented Dec. '2, 1890.

I wmwm 1' a w flo BEST ners cost UNITE STATES PATENT OFFICE.

EDWIN T. GREEXFIELD AND -J UK III-S NAGEL, OF NEW YORK, X. Y., ASSIGNORS,

' BY MESNE COMPANY.

ASSIGNMEIQTS, TO THE INTERIOR CONDUIT AND INSULATION TUBE.

SPECIFICATION forming part of Letters Patent No. {142,090, dated December 2, 1890.

Application filed Kay 27, 1890.

To all whom it may concern: 7

v Belt known that we, EDWIN 'l. GBEENFIELD,

a citizen of the United States, and JUNIUs 'NAGEL, (who has declared hisintention of becoming a citizen of the United States,) both residing at New York city, in the county and State of New York, have invented a new and Improved Tube, of which the following is a specification.

The advantages of employing .tubes possessing insulating qualities as conduits for I electric conductors has long been known.

Among other kinds of tubes used have been those formed by highly compressing paper-v pulp into the desired form and depf nding upon the compressed pulp only for insulation. Another and the most common kind for economical tubes has been a tube formed of layers of paper coated with a bituminous compound, as pitch, which served both to retain the tube in proper form and add to its insulatin properties. This latter tube was not homo eneous, and proved objectionable in use, as did the first-mentioned kind, notwithstanding any advantages they might possess from a standpoint of economy 1n first cost, in that among other things they. were afiect'ed by dampness to such a degree as to materially lessen their durability and insulating properties. It has also been proposed to use tubes of a' bituminous compound com bined with a material added in a pulpform, the tube being made by'squirtm g the nuxtu re "through a die." This form of tube is diflicult of manufacture, and therefore expensiye, and the tubes produced were likely to be irregular' in composition, besides 1t being impossible. to make them of considerable length.

The tube which we have invented is economical in first cost, is homogeneous, possesses high insulating properties, is strong, durable,

and not affected by hygrometricor ordinary thermalchanges; and it consists, essentially,

of aformedbasc of twoor morethickness or layerect a porous fibrous mater alsuch as felt -paper'-and a filling of a bituminous material or compound-such as black petroleum pitch-izombinedwith the porous fibrous ma- .terial throughout its mass, the whole forming so a compound tube possessing the chaMteris- Serial No.353,362. (No model.)

nous compound by its greater density throughout its mass, which will appear by cutting, which will show that the tube has lost almost wholly the physical structure v of its componeutmaterials and assumed new characteristics possessed by none of those materials separately. The brittle character of the bituminous material or compound, which would be a serious objection to its use alone for a tube, is supplemented by the fibrous character of the formed base, which imparts the desirable strength, and the hygroscopic character of the formed base is supplemented by the bituminous compound, which efiectually obviates all tendency in the compound tube to absorb moisture.

The fibrous porous material which I make use of as a base may be either of a vegetable nature, as sheathing-paper, or of an animal nature, as felt paper, or of a mineral nature, as asbestos When made of animal or vegetable fiber, the base is firstformed in the desired shape, preferably for large sizes, by serving longitudinal layers thereof one over the other,eaclr layer breaking joint with its next inner layer, and for small sizes. by a longitudinal core with a' spiral wrap or wrappin-gs. When asbestus is used as the base, the tube is first formed in any (lesirableinan nor-as, for instance, by wrappinga sheet of ,what is knownas asbestos paper in concentric layers on a mandrel. The material which we prefer to use as the base for the tubes of large size is that known as felt paper, which possesses an exceedingly open porous structure, well adapted for combining throughout its mass with the filling material or compound.

For smaller siies of tubing. we prefer to make use as a base of what is known as sheathing-paper, which possesses a somewhat less open or porous structure than the felt paper, but is yet suff ciently open t-Qcombiue with a large quantity of-the filling material or compound throughout its mass.

The large size, tubingis especially adapted for use. as a conduit in a system of under ground distribution where difliculties from moisture are most to be apprehended, while the small tubing is especially adaptedfor use as a conduit for interior systems-of distribuw tion'where danger from moisture is loss great, and where; therefore, the small sizes do not re: uire the presence of so much compound as do the conduits for undergroundwork. The

papefbasehaving been shaped'from the required quality of animal or vegetable porous material, 3 then constitutes what I have termed I a formcd base, and is ready to hnvecon bined with it the filling compound .or n material,

I which is done in the following mannerz The I compound is maintained in asuitable kettle in a liquidcondition; by heat,- the best workrun freely like, water.

' ing condition being attained when they com- I *immcrsedand-fle immersion followed by a second period of" i est, and. this operation of alternate immersions and rests. is continued until there i'sa' thoroughcombination of the filling niaterialwith the material, of the bases.

- Fora base one inch in internal diameter with a wall tnreeeigntns ncn micrzness made of felt. paper wleiind that. the-followin g .periods of immersions and rests, using black petroleum-pitch as the fillerg will produce a compound tubeflhomogeneous.in physical characteristics.

Agtire'lve-incli length of felt of the diameter'and thickness of .wall above statedwill weigh four-ounces. W hen combined with. the filler; by the process above set on t, itffwill weigh twelve ounces without having i ncreased perceptiblyin dimensionsf Such a compound tube is u el-llndapted. undergroundconi duits.

eighths inch internal diameter with a wall only.

sixteenth inch thickness, using lilac-i: petril .leunrpitclfas a filler; we find that the following periods of rests and immersions will pro duce a homogeneous tube.

Kohof innnersions. Ilnmersions minutes. Rests minutes.

I- 1 1T 3 v l 4 1 m 5 i i A twelve-inch length of a base. made of sheathing-paper having-an internal-diameter of three-eighths inch and a wall of one-sixteenth of an inch in thickness willweigh one and three-quarter ounces. When combined with the tiller by the process above set forth it will eigh two and three-quarter ounces without having increased perceptibly in di mensions. Such a tube is well adapted as a conduit for interior wiring. r V When amineral fibrous material is used as a base, the samemay have the filler combined with itwithout employin g the process of alternate immersions and rests above set forth, as there is no danger of charringthemiueral fiber, although even with mineral fiber we prefer to employ this process .for combining the base and filler. Y

' We have described the new tube of 'our-iuvention as especially useful as a conduit for electric conductors; but it is apparent that it instance, for the conveyance of fluids and gases; and for speaking-tubes, the.

in the accompanying drawings, forming a part of this specification, Figure l is a" plan View of the formed base foraIarge-sizedtube. Fig. 2 is a transversesection thereof. Fig. 8 is a plan view of the formed base for atube of small size. thereof. base of ashestus, and Fig. 6 is a cross-section of any of the above tubes after the filler has been combined therewit I In l and 2, a is the inner longitudinally-served layer of feltpaper, or other .suitableporous fibrous material. Preferably this layer is arranged so that its meeting edges i abutto'forn the Beam 1). c is thenext longitudinally-applied layer, the edges of which also abut, and are arranged so that the seam (Z breaks. joint with the scam I). e is the on tellayer,'..applied in the same; manneras-the re nsurance, and the scam j breaks joint with t-heseam (Z of the next inner layer. Jr

P 4 is a.t-ran'sverse section Big. 5 is an end view of a formed stripof thin paper ginay-be pasted over the seam so that the formed basewill be held in its. true shapewhile being combined with I' the filler. As many layers of the felt or other suitable material may be employed as may befoiin'd desirable to make the necessary thickness of tube, depcndinggof 'course,'upon p H p I ..thc thicknessofeach individualilayer. For a baseofisheathmg-paper of threel'n Figsil and 4', it is the internal core of the formed base, which is a fillet of sheathn'g-paper or ,other suitable material having asean b. Around this longitudinal seamedcore a spiral wrap or wrappings of suitable material j are applied. This sheathing of paper is not quite so open or porous as is the felt paper; but it is sufficiently open and porous to combine with a considerable quantity of the filling material or compound.

Fi shows asheet of mineral fiber asbestus formed byasinglc sheet wrapped in conoentrio layers.

Fig. 6 is a cross-section of a treated tube, showing, as far as a drawing can, that when the filler is combined with the formed base the result is a tube homogeneous throughout its mass. 7

What we claim as our invention is-- 1. As a new article of manufacture, a compound tube comprising a formed base of two or more thicknesses of aporous fibrous material and a filling of bituminous niateriai or compound combined with said formed base throughout itsmass, substantially as specified.

base throughout its mass, substantially as specified.

This specification signed and Witnfssed'this 15th (layof May, 1890.

EDWIN 'r. GREENFI'EL J UN IUS NAGEL.

Wi tn esses: C.-S. CHAMPION, W. PELZER. 

